Mashhad University of Medical SciencesIranian Journal of Medical Physics2345-367211Issue 2,320140801Non-invasive Optical Techniques for determination of blood Glucose levels: A Review Article224232309410.22038/ijmp.2014.3094ENNeda JahangiriDepartment of Photonics, Kerman University of Technology, Kerman, IranAlireza BahrampourDepartment of Physics, Sharif University of Technology, Tehran, IranMajid TarazDepartment of Physics, Shahid Bahonar University of Kerman, Kerman, IranJournal Article20130921This article reviews the development of non-invasive optical techniques for determination of blood glucose concentrations in diabetic patients. Early diagnosis and daily management are essential for ensuring the healthy life of diabetic patients. The determination of blood glucose concentration with common devices involves the chemical analysis of blood samples, which are obtained by pricking the finger or extracting blood from the forearm. Pain, discomfort, and inconvenience, associated with current invasive methods, have necessitated the investigation of non-invasive measurement techniques. Non-invasive monitoring of blood glucose level offers several advantages, including absence of pain and biohazard materials, non- exposure to sharp objects, increased testing frequency and consequently, tighter control of glucose concentration. Considering these potential advantages commercialization of non-invasive glucose monitoring devices has become a subject of increasing interest. Several optical technologies have the potential to provide viable non-invasive measuring devices. this review study aimed to describe the major optical technologies for non-invasive glucose monitoring and compare their advantages and disadvantages. <br/>second scenario) better than other methods in presence of a typically low false positive rate equal to 3%.Mashhad University of Medical SciencesIranian Journal of Medical Physics2345-367211Issue 2,320140801Prediction of Above-elbow Motions in Amputees, based on Electromyographic(EMG) Signals, Using Nonlinear Autoregressive Exogenous (NARX) Model233241309510.22038/ijmp.2014.3095ENAli Akbar AkbariDepartment of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, IranMahdi TalasazDepartment of Mechatronics Engineering, Islamic Azad University, South Tehran Branch, Tehran, IranJournal Article20131103Introduction <br/>In order to improve the quality of life of amputees, biomechatronic researchers and biomedical engineers have been trying to use a combination of various techniques to provide suitable rehabilitation systems. Diverse biomedical signals, acquired from a specialized organ or cell system, e.g., the nervous system, are the driving force for the whole system. Electromyography(EMG), as an experimental technique,is concerned with the development, recording, and analysis of myoelectric signals. EMG-based research is making progress in the development of simple, robust, user-friendly, and efficient interface devices for the amputees. <br/>Materials and Methods <br/>Prediction of muscular activity and motion patterns is a common, practical problem in prosthetic organs. Recurrent neural network (RNN) models are not only applicable for the prediction of time series, but are also commonly used for the control of dynamical systems. The prediction can be assimilated to identification of a dynamic process. An architectural approach of RNN with embedded memory is Nonlinear Autoregressive Exogenous (NARX) model, which seems to be suitable for dynamic system applications. <br/>Results <br/>Performance of NARX model is verified for several chaotic time series, which are applied as input for the neural network. The results showed that NARX has the potential to capture the model of nonlinear dynamic systems. The R-value and MSE are and , respectively. <br/>Conclusion <br/> EMG signals of deltoid and pectoralis major muscles are the inputs of the NARX network. It is possible to obtain EMG signals of muscles in other arm motions to predict the lost functions of the absent arm in above-elbow amputees, using NARX model.Mashhad University of Medical SciencesIranian Journal of Medical Physics2345-367211Issue 2,320140801Design and Evaluation of a Pressure and Temperature Monitoring System for Pressure Ulcer Prevention242252309710.22038/ijmp.2014.3097ENFarve Daneshvar FardDepartment of Electrical Engineering, Ferdowsi University of Mashhad, Mashhad, IranSahar MoghimiDepartment of Electrical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
& Center of Excellence on Soft Computing and Intelligent Information ProcessingReza LotfiDepartment of Electrical Engineering, Ferdowsi University of Mashhad, Mashhad, IranJournal Article20131208Introduction <br/>Pressure ulcers are tissue damages resulting from blood flow restriction, which occurs when the tissue is exposed to high pressure for a long period of time. These painful sores are common in patients and elderly, who spend extended periods of time in bed or wheelchair. In this study, a continuous pressure and temperature monitoring system was developed for pressure ulcer prevention. <br/>Materials and Methods <br/>The monitoring system consists of 64 pressure and 64 temperature sensors on a 40×50 cm2 sheet. Pressure and temperature data and the corresponding maps were displayed on a computer in real-time. Risk assessment could be performed by monitoring and recording absolute pressure and temperature values, as well as deviations over time. Furthermore, a posture detection procedure was proposed for sitting posture identification. Information about the patient’s movement history may help caregivers make informed decisions about the patient’s repositioning and ulcer prevention strategies. <br/>Results <br/>Steady temporal behaviour of the designed system and repeatability of the measurements were evaluated using several particular tests. The results illustrated that the system could be utilized for continuous monitoring of interface pressure and temperature for pressure ulcer prevention. Furthermore, the proposed method for detecting sitting posture was verified using a statistical analysis. <br/>Conclusion <br/>A continuous time pressure and temperature monitoring system was presented in this study. This system may be suited for pressure ulcer prevention given its feasibility for simultaneous monitoring of pressure and temperature and alarming options. Furthermore, a method for detecting different sitting postures was proposed and verified. Pressure ulcers in wheelchair-bound patients may be prevented using this sitting posture detection method.Mashhad University of Medical SciencesIranian Journal of Medical Physics2345-367211Issue 2,320140801Size Effects of Gold and Iron Nanoparticles on Radiation Dose Enhancement in Brachytherapy and Teletherapy: A Monte Carlo Study253259309810.22038/ijmp.2014.3098ENAhad Ollah EzzatiFaculty of Physics, University of Tabriz, Tabriz, Iran0000-0003-2594-6938Seyed Rabi MahdaviDepartment of Medical Physics, Iran University of Medical Sciences, Tehran, Iran0000-0003-1973-2140Hossein Mousavie AnijdanDepartment of Medical Physics, Babol University of Medical Sciences, Babol, IranJournal Article20131103Introduction <br/>In this study, we aimed to calculate dose enhancement factor (DEF) for gold (Au) and iron (Fe) nanoparticles (NPs) in brachytherapy and teletherapy, using Monte Carlo (MC) method. <br/>Materials and Methods <br/>In this study, a new algorithm was introduced to calculate dose enhancement by AuNPs and FeNPs for Iridium-192 (Ir-192) brachytherapy and Cobalt-60 (Co-60) teletherapy sources, using the MC method. In this algorithm, the semi-random distribution of NPs was used instead of the regular distribution. Diameters were assumed to be 15, 30, and 100 nm in brachytherapy and 15 and 30 nm in teletherapy. Monte Carlo MCNP4C code was used for simulations, and NP density values were 0.107 mg/ml and 0.112 mg/ml in brachytherapy and teletherapy, respectively. <br/>Results <br/>AuNPs significantly enhanced the radiation dose in brachytherapy (approximately 60%), and 100 nm diameter NPs showed the most uniform dose distribution. AuNPs had an insignificant effect on teletherapy radiation field, with a dose enhancement ratio of 3% (about the calculation uncertainty) or less. In addition, FeNPs had an insignificant effect on both brachytherapy and teletherapy radiation fields. FeNPs dose enhancement was 3% in brachytherapy and 6% (about the calculation uncertainty) or less in teletherapy. <br/>Conclusion <br/>It can be concluded that AuNPs can significantly increase the absorbed dose in brachytherapy; however, FeNPs do not have a noticeable effect on the absorbed doseMashhad University of Medical SciencesIranian Journal of Medical Physics2345-367211Issue 2,320140801Contrast Enhancement of Mammograms for Rapid Detection of Microcalcification Clusters260269310010.22038/ijmp.2014.3100ENHajar MoradmandDepartment of Biomedical-Radiation Engineering, Amirkabir University of Technology, Tehran, IranSaeed SetayeshiDepartment of Biomedical-Radiation Engineering, Amirkabir University of Technology, Tehran, IranAlireza KarimianDepartment of Biomedical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, IranMehri SirousDepartment of Radiology, Isfahan University of Medical Sciences, Isfahan, IranJournal Article20130409Introduction <br/>Breast cancer is one of the most common types of cancer among women. Early detection of breast cancer is the key to reducing the associated mortality rate. The presence of microcalcifications clusters (MCCs) is one of the earliest signs of breast cancer. Due to poor imaging contrast of mammograms and noise contamination, radiologists may overlook some diagnostic signs, specially the presence of MCCs. In order to improve cancer detection, image enhancement methods are often used to aid radiologists. In this paper, a new enhancement method was presented for the accurate and early detection of MCCs in mammograms. <br/>Materials and Methods <br/>The proposed system consisted of four main steps including: 1) image scaling;2) breast region segmentation;3) noise cancellation using a filter, which is sensitive to MCCs; and 4) contrast enhancement of mammograms using Contrast-Limited Adaptive Histogram Equalization (CLAHE) and wavelet transform. To evaluate this method, 120 clinical mammograms were used. <br/>Results <br/>To evaluate the performance of the image enhancement algorithm, contrast improvement index (CII) was used. The proposed enhancement method in this research achieved the highest CII in comparison with other methods applied in this study. The Validity of the results was confirmed by an expert radiologist through visual inspection. <br/>Conclusion <br/>Detection of MCCs significantly improved in contrast-enhanced mammograms. The proposed method could be helpful for radiologists to easily detect MCCs; it could also decrease the number of biopsies and reduce the frequency of clinical misdiagnosis. Moreover, it could be useful prior to segmentation or classification stages.Mashhad University of Medical SciencesIranian Journal of Medical Physics2345-367211Issue 2,320140801Optimization of Parameters in 16-slice CT-scan Protocols for Reduction of the Absorbed Dose270275310110.22038/ijmp.2014.3101ENShahrokh NaseriMedical Physics Dept., Mashhad University of Medical Sciences, Mashhad,IranMahdi Momen NezhadMedical Physics Dept., Mashhad University of Medical Sciences, Mashhad,IranZahra HozhabriMedical Physics Dept., Kermanshah University of Medical Sciences, Kermanshah,IranAbbas HaghparastMedical Physics Dept., Kermanshah University of Medical Sciences, Kermanshah,IranGolestan KaramiMedical Physics Dept., Kermanshah University of Medical Sciences, Kermanshah,IranPeyman HejaziMedical Physics Dept., Semnan University of Medical Sciences, Semnan, IranJournal Article20140310Introduction <br/>In computed tomography (CT) technology, an optimal radiation dose can be achieved via changing radiation parameters such as mA, pitch factor, rotation time and tube voltage (kVp) for diagnostic images. <br/>Materials and Methods <br/>In this study, the brain, abdomen, and thorax scaning was performed using Toshiba 16-slice scannerand standard AAPM and CTDI phantoms. AAPM phantom was used for the measurement of image-related parameters and CTDI phantom was utilized for the calculation of absorbed dose to patients. Imaging parameters including mA (50-400 mA), pitch factor (1 and 1.5) and rotation time (range of 0.5, 0.75, 1, 1.5 and 2 seconds) were considered as independent variables. The brain, abdomen and chest imaging was performed multi-slice and spiral modes. Changes in image quality parameters including contrast resolution (CR) and spatial resolution (SR) in each condition were measured and determined by MATLAB software. <br/>Results <br/>After normalizing data by plotting the full width at half maximum (FWHM) of point spread function (PSF) in each condition, it was observed that image quality was not noticeably affected by each cases. Therefore, in brain scan, the lowest patient dose was in 150 mA and rotation time of 1.5 seconds. Based on results of scanning of the abdomen and chest, the lowest patient dose was obtained by 100 mA and pitch factors of 1 and 1.5. <br/>Conclusion <br/>It was found that images with acceptable quality and reliable detection ability could be obtained using smaller doses of radiation, compared to protocols commonly used by operators.Mashhad University of Medical SciencesIranian Journal of Medical Physics2345-367211Issue 2,320140801Echocardiographic Assessment of Left Ventricle Torsion by Tissue Doppler and Velocity Vector Imaging276283310310.22038/ijmp.2014.3103ENZahra Ojaghi-HaghighiEchocardiography Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IranAzin AlizadehaslEchocardiography Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IranAtoosa MostafaviEchocardiography Research Center, Shariati Medical and Research Center, Tehran University of Medical Sciences, Tehran, IranHassan MoladoustCardiovascular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, IranNasim NaderiDepartment of Heart Failure and Transplantation, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IranFeridoun NoohiEchocardiography Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IranMajid MalekiEchocardiography Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IranVahid NiksereshtCardiovascular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, IranJournal Article20130531Introduction <br/>Left ventricular (LV) twist is believed to store potential energy and plays an important role in generating diastolic suction. Recent advances in echocardiography techniques have allowed quantification of LV twist. The aim of the present study was to compare LV twist and torsion in healthy human subjects determined by velocity vector imaging (VVI) and tissue Doppler imaging (TDI) at rest. <br/>Materials and Methods <br/>All volunteers (72 healthy subjects) underwent complete echocardiographic study and LV torsional parameters were assessed using VVI or TDI methods. LV rotation at apical and basal short-axis levels was calculated throughout cardiac cycle and LV twist was defined as net difference between rotation angles of the two levels. The LV torsion was calculated as the LV twist divided by the LV end-diastolic length. <br/>Results <br/>Twist degree was significantly lower in the VVI group than the TDI group (11.4±2.4º vs.14.1±3.0º, p<0.001), but when LV twist was normalized by LV end-diastolic length, there was no statistically significant difference between the two groups (1.9±0.7 º/cm vs. 2.1±0.6 º/cm, p=0.142). <br/>Conclusion <br/>Normalized LV twist or LV torsion values were comparable for both imaging techniques (TDI and VVI methods). Results suggest that these methods may be interchanged for serial assessment, but needs additional studies and preferably larger populations to confirm it.Mashhad University of Medical SciencesIranian Journal of Medical Physics2345-367211Issue 2,320140801Automatic Sperm Analysis in Microscopic Images of Human Semen: Segmentation Using Minimization of Information Distance284293310410.22038/ijmp.2014.3104ENSeyed Vahab ShojaediniElectrical and Computer Engineering Department, Iranian Research Organization for Science and Technology, Tehran, Iran.Masoud HeydariElectrical and Computer Engineering Department, Iranian Research Organization for Science and Technology, Tehran, IranJournal Article20131103Introduction <br/>The morphologic features of human sperms are key indicators for monitoring fertility problems in men. Therefore, automated analyzing methods via microscopic videos have become the most favorite policy in infertility treatment during the last decades. <br/>Materials and Methods <br/>In the proposed method, firstly a hypothesis testing framework was defined to distinguish sperms from background. Then, some regions were selected as candidates by minimization of the information distance between the original and processed images. Finally, the correct sperms were extracted from candidates using a watershed-based algorithm. <br/>Results <br/>The proposed, Watershed Segmentation Algorithm (WSA), Multi Structure Element Segmentation (MSES) and Dynamic Threshold Segmentation (DTS) algorithms achieve true positive rates of 96%, 84%, 81%, and 70%, respectively, versus typically 3% of false positive rate in semen specimens with high density of sperms. The true positive rates of 87%, 69%, 66%, and 52%, respectively, at the same false positive rate were obtained for the semen specimens with high density of sperms. <br/>Conclusion <br/>Results show that false positive rates of the proposed algorithm were at least 8% (in the first scenario) and 32% (in the second scenario) better than other methods considering the minimum acceptable true positive rate of 90%. Furthermore, it has been shown that the proposed algorithm extracted sperms at least 12% (in the first scenario) and 18% (in the second scenario) better than other methods in presence of a typically low false positive rate equal to 3%.